Goodwill and Intangibles - Intangible Assets and Accumulated Amortization Balances (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 199,235	$ 200,235
Accumulated Amortization	(133,372)	(132,556)
Net Carrying Amount	65,863	67,679
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	154,510	155,409
Accumulated Amortization	(122,837)	(122,657)
Net Carrying Amount	31,673	32,752
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	44,725	44,826
Accumulated Amortization	(10,535)	(9,899)
Net Carrying Amount	$ 34,190	$ 34,927